Supplemental instruction 1/23/2018 BIOL 211 Exam 1 review Supplemental instruction 1/23/2018

Characteristics of science Hypothesis: statement about the universe. Can be based on past experience and/or available data called facts. Facts: things that happen and can be objectively observed. Theories: explain why things happen. Science: a fact-driven exercise in understanding the universe. What are the 5 characteristics of science? Testable Falsifiable Measurable Reproducible Objective

“Biologists practice evidence based decision making…” Turn to a partner. In your own words, what does this statement mean? Simply stated, “Biologists select a hypothesis and an invalid hypothesis based on prior experiments or observational data.”

5 steps to scientific method Formulate hypothesis Design experiment Test hypothesis Reject or fail to reject hypothesis Revise hypothesis or move on to new hypothesis arising from process

Characteristics of living things Regulate internal conditions Reproducible Evolve Use energy Respond to environment Composed of one or more cells Grow

Viruses 3 hypotheses regarding the origin of viruses… Progressive: viruses arose from mobile genetic elements Regressive: viruses evolved from small cells that were parasites of larger cells Virus-first: viruses evolved before their hosts as simple, self-replicating units that overtime became more complex. Viruses are the ancestors of the first cells.

Lytic vs. Lysogenic reproductive cycle The viral nucleic acids are incorporated into the genome of its host is called the..? Uses host reproductive machinery to replicate itself and destroys the host in the process..? Lysogenic reproductive cycle Lytic reproductive cycle

Prokaryotes Oldest organisms Very diverse Extremely abundant Microscopic and really small Unicellular Little internal organization 2 Domains: Bacteria and Archaea

3 methods of bacterial reproduction Conjugation: genetic material is transferred between two cells that are temporarily joined. Transduction: bacteriophages carry bacterial genes from one host cell to another. Transformation: the genetic material in a cell is altered by the uptake of foreign DNA from the cell’s surroundings.

PRotists ”Endosymbiont Theory” The ancestors of eukaryotic cells were once in a symbiotic relationship with prokaryotic cells. Which means, mitochondria are the descendants of aerobic heterotrophic bacteria Chloroplasts are the descendants of photosynthetic bacteria – cyanobacteria

No SI Friday! Good luck on your test! Next session will be Monday, January 29th, from 2:10 to 3pm in Gilman 1051.